1. Field of the Invention
The present invention relates to an apparatus and method for detecting biomolecule bonding using radio frequency (RF) wireless energy transmission and a method thereof and, more particularly, to an apparatus and method for detecting biomolecule bonding by determining a time differential for charging a sensor module through transmission of RF wireless energy, wherein the charging time depends upon the extent of biomolecule bonding of probe biomolecules immobilized on the sensor module.
2. Description of the Related Art
A biomolecule chip is a biological microchip having biomolecules immobilized on a substrate. Biomolecule chips can be categorized based on the type of immobilized biomolecule, for example, DNA chips, protein chips, etc. A biomolecule which is immobilized on a chip and binds with a target biomolecule in a sample is called a probe. Biomolecule chip-related technical fields in development include, for example: biomolecule immobilization techniques for immobilizing biomolecules on a substrate, techniques for bonding immobilized biomolecules on a biomolecule chip with components of a sample, and biomolecule detection techniques for detecting the existence and the kind of biomolecules based on the analysis of a biomolecule chip where unknown biomolecules are immobilized.
Presently, there are several signal detection techniques in existence for the detection of biomolecule bonding. Broadly stated, these techniques may be classified into categories such as, for example, optical biomolecule bonding detection, chemical biomolecule bonding detection, mechanical biomolecule bonding detection, and electrical biomolecule detection, etc.
A conventional optical biomolecule bonding detection method is a method for optically determining whether a probe biomolecule is bonded to components of a sample. In order to detect the biomolecule bonding based on the optical biomolecule bonding detection method, biomolecule sample is labeled with a fluorescent material and is reacted with the probe biomolecule on the biomolecule chip such that ligands in the sample can bind with the probe biomolecule. The results of the reaction are then analyzed using a fluorescent detecting device so as to optically determine the amount of bonding with the probe biomaterials. However, the optical biomolecule bonding detecting method requires a pretreatment for mixing the fluorescent material with sample biomolecules before the sample is reacted with the probe. Therefore, the sample may be damaged or contaminated by the fluorescent material. A high-cost optical reader is also required for analyzing the result, and it is very complicated to analyze the result by using the optical reader. Furthermore, digitized data is not provided from the optical detection devices. Moreover, it is very difficult to miniaturize an optical detection apparatus.
Conventional mechanical biomolecule bonding detection methods detect a mechanical variation by utilizing an apparatus such as a cantilever, a surface acoustic wave (SAW) biosensor, or a scanning probe microscope (SPM). Where a cantilever is used, the biomolecule bonding is detected by measuring and comparing intermolecular cohesions before and after the probe biomolecule reacts with the sample biomolecule. In order to measure the intermolecular cohesion, the deflection of cantilever beam must be accurately measured. Therefore, the mechanical biomolecule bonding detection method requires supplementary equipment such as a laser.
Detection through a SAW biosensor utilizes the input of a signal at a predetermined frequency to a SAW filter, and the sample biomolecule reacts with the probe biomolecule on the SAW filter. The biomolecule bonding is detected by observing a filtering variation of the SAW filter generated by reaction of the sample biomolecule and the probe biomolecule. The mechanical biomolecule bonding detection method using the SAW requires additional equipment such as a laser device and a photo diode.
Conventional chemical biomolecule bonding detection methods detect the presence and absence of biomolecule bonding by analyzing the degree of electrochemical reaction of other chemical materials on an electrode on which probe biomolecules and sample biomolecules bind with each other. However, this method provides an inferior detection capability in comparison to optical biomolecule bonding detection methods.
In addition, conventional electrical biomolecule bonding detection methods may use structures such as, for example, a trench-type capacitance element or a planar-type capacitance element. However, since capacitance is proportional to cross sectional area and inversely proportional to thickness, it is difficult to design and form a capacitance element having an increased cross sectional area together while also ensuring efficient bio processing.
In particular, a detection method using a trench-type capacitor provides a method of reducing thickness and increasing cross sectional area of the capacitor by forming a deep trench, however it is not useful for bio processing since the resulting gap is very small. In contrast, a biomolecule bonding detection method using a capacitor in which a capacitance element is formed with a comb shape on a plane is disadvantageous in that only a relatively small number of capacitance elements are formed, since the metal film has a small thickness, and the detection sensitivity for biomolecules bonding is poor.